Cylinder 4 Deactivation/Intake Valve Control Circuit Low
The engine control module (ECM) detected that the voltage in the control circuit for the cylinder 4 deactivation or intake valve solenoid is lower than the manufacturer's specified range. This indicates a fault in the system responsible for shutting down cylinder 4 during light-load driving conditions to improve fuel economy.
While the vehicle can typically still be driven, the cylinder deactivation system will be disabled, leading to reduced fuel economy and potential rough running. It should be diagnosed soon to prevent further stress on the valvetrain.
Common symptoms
- Illuminated Check Engine Light
- Decreased fuel economy
- Engine running rough or vibrating
- Hesitation during acceleration
- Cylinder deactivation system disabled
Likely causes
- Low engine oil level or dirty oil
- Faulty cylinder 4 deactivation solenoid
- Wiring harness shorted to ground or damaged
- Poor electrical connection at the solenoid
- Restricted oil passages to the lifters
- Failing Engine Control Module (ECM)
What to check before replacing parts
Check the engine oil level and condition.
Look for: Low oil levels or excessively dirty oil can prevent the hydraulic cylinder deactivation system from operating correctly.
Visually inspect the wiring and connector for the cylinder 4 deactivation solenoid.
Look for: Look for chafed wires, melted insulation, or corroded pins that could cause a short to ground or high resistance.
Measure the resistance of the cylinder 4 deactivation solenoid using a multimeter.
Look for: Compare the resistance reading to the manufacturer's specifications; an out-of-range reading indicates an internal short or failure in the solenoid.
Test the control circuit for proper voltage and ground signals from the ECM.
Look for: With the system commanded on, verify that the ECM is supplying the correct voltage; a lack of voltage indicates a wiring issue or ECM fault.
Perform an engine oil pressure test.
Look for: Ensure the engine is producing sufficient oil pressure, as the deactivation solenoids rely on adequate hydraulic pressure to actuate the lifters.
This page explains the generic P3427 definition and is general reference information, not a diagnosis for your specific vehicle. Actual causes, severity, and repairs vary by make, model, engine, and mileage — always confirm with a scan tool and a qualified technician before replacing parts.
Gear guide: Best OBD2 ScannersRead this code yourself next time — from $20 Bluetooth dongles to bidirectional scan tools.Rather have a pro handle it? Find a vetted local mechanic.